First of all, we need to be aware that some flavours only dissolve in water, while others only dissolve in fats.
This phenomenon leads to this kind of accident: If you put a
chocolate mousse uncovered in the fridge where you are also keeping fish, the chocolate, being mostly made up of cocoa butter (a fat), will absorb the fish smell. Imagine the taste…
So we have water on the one side and fats on the other. Cream seen under the microscope is made up of water with minute fat globules (which come from milk) suspended in it.
This gives us the explanation: the make up of cream allows it to absorb both types of flavours, so it can absorb virtually all flavours. This means that cream produces sauces which are always full of flavour drawn from everything around it (whatever is stuck on the bottom of the pan, the ingredients in the recipe, etc.).
Add to this that during cooking a proportion of the cream will evaporate, and this means that it will thicken and give a rich smooth texture in the mouth – perfect!
And then there's the question of all those calories, but that's quite another matter…